Randomized evaluation of ticagrelor monotherapy after 3-month dual-antiplatelet therapy in patients with acute coronary syndrome treated with new-generation sirolimus-eluting stents: TICO trial rationale and design

Clinical implication of ticagrelor monotherapy in patients with small vessel coronary artery disease: results from the TICO randomized trial

Background

The aim of this study was to evaluate the efficacy and safety of ticagrelor monotherapy in patients with small vessel disease compared with ticagrelor-based DAPT within the Ticagrelor Monotherapy after 3 Months in the Patients Treated with New Generation Sirolimus Eluting Stent for Acute Coronary Syndrome (TICO) trial population.

Methods

Reference vessel diameter ≤2.5 mm was considered as small vessel disease. We conducted a comparison of the incidence of target lesion failure (TLF) and Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding. TLF was defined as a composite of cardiac death, target lesion myocardial infarction, stent thrombosis, and target lesion revascularization.

Results

652 patients among 3,056 TICO population (21.3%) had small vessel disease. Patients with small vessel disease showed a higher rate of TLF compared to those without small vessel disease (2.9% vs. 1.0%, log-rank p < 0.001). The presence of small vessel disease emerged as an independent predictor for 1-year TLF (HR 2.84, 95% CI 1.54-5.25), while it did not show a significant association with bleeding complications. The 12-month TLF rate was 1.6% for ticagrelor monotherapy after 3-month DAPT, and 4.2% for ticagrelor-based 12-month DAPT (p = 0.059) in patients with small vessel disease (HR 0.38, 95% CI 0.14-1.04, p for interaction = 0.261). The incidence of BARC type 3 or 5 bleeding rate 2.5% for ticagrelor monotherapy after 3-month DAPT, and 5.6% for ticagrelor-based 12-month DAPT (p = 0.052) in patients with small vessel disease (HR 0.44, 95% CI 0.19-1.01, p for interaction = 0.322). In the 3-month landmark analysis, ticagrelor monotherapy significantly reduced BARC type 3 or 5 bleeding in patients with small vessel disease (HR 0.09, 95% CI 0.01-0.69, log-rank p = 0.005) while demonstrating a similar incidence of TLF compared to ticagrelor based 12-month DAPT during the 3-12 months period.

Conclusions

There are no significant interactions between the antiplatelet strategy regarding the 12-month incidence of ischemic and bleeding complications. Ticagrelor monotherapy demonstrated a reduction in bleeding complications after a 3-month period of DAPT without increasing the rate of TLF, when compared to ticagrelor-based 12-month DAPT, specifically in patients with small vessel disease. Clinical Trial Registration: www.ClinicalTrials.gov, identifier, NCT02494895.

Long-term use of clopidogrel versus ticagrelor or prasugrel in patients with acute myocardial infarction after percutaneous coronary intervention

BACKGROUND AND OBJECTIVES

To compare the long-term clinical outcomes of dual antiplatelet therapy (DAPT) with clopidogrel and DAPT with ticagrelor or prasugrel in patients with acute myocardial infarction (AMI) who underwent coronary intervention.

METHODS

Between November 2011 and December 2015, a total of 13,104 patients with AMI were enrolled in the Korea Acute Myocardial Infarction Registry-National Institutes of Health (KAMIR-NIH) registry. Among them, 4,696 patients who received DAPT for more than 24 months were categorized into two groups: the clopidogrel group (n = 4,053) and ticagrelor or prasugrel group (n = 643). Propensity score matching (PSM) was used to reduce the bias due to confounding variables. Following PSM, the impacts of P2Y12 inhibitors on the clinical outcomes in both groups were compared during a 36-month clinical follow-up period.

RESULTS

There were no significant differences in clinical outcomes in terms of cardiac death (7.1% vs. 9.7%, p = 0.101), stroke (1.4% vs. 1.0%, p = 0.436), major bleeding (0.5% vs. 0.8%, p = 0.478), major adverse cardiac events (MACE) (21.6% vs. 20.5%, p = 0.626), and net adverse cardiac event (NACE) (22.1% vs. 21.3%, p = 0.731) between the groups. The ticagrelor or prasugrel group had a lower incidence of recurrent percutaneous coronary intervention (PCI) (12.2% vs. 7.6%, p = 0.006) than the clopidogrel group. However, no differences were observed in the cumulative incidences of 3-year NACE between the ticagrelor or prasugrel and clopidogrel groups.

CONCLUSIONS

Cumulative incidences of long-term NACE did not differ between the two groups. Therefore, the type and duration of DAPT should be customized for each patient with AMI.

Body mass index affecting ticagrelor monotherapy vs. ticagrelor with aspirin in patients with acute coronary syndrome: A pre-specified sub-analysis of the TICO randomized trial

Background

Although ticagrelor monotherapy after 3-month dual antiplatelet therapy (DAPT) results in a significantly greater net clinical benefit over that with ticagrelor-based 12-month DAPT in patients with acute coronary syndrome (ACS), it remains uncertain whether this effect is dependent on body mass index (BMI). We aimed to evaluate the BMI-dependent effect of these treatment strategies on clinical outcomes.

Methods

This was a pre-specified subgroup analysis from the TICO trial (Ticagrelor Monotherapy After 3 Months in Patients Treated With New Generation Sirolimus-eluting Stent for Acute Coronary Syndrome), evaluating the interaction between BMI and treatment strategies for the primary outcome [composite of major bleeding and adverse cardiac and cerebrovascular events (MACCE): death, myocardial infarction, stent thrombosis, stroke, or target-vessel revascularization]. The secondary outcomes were major bleeding and MACCE.

Results

Based on a pre-specified BMI threshold of 25 kg/m², 3,056 patients were stratified. Patients with BMI <25 kg/m² had a higher risk of primary and secondary outcomes than those with BMI ≥25 kg/m². Regardless of the BMI subgroup, the effects of ticagrelor monotherapy after 3-month DAPT on the primary outcome (p _int= 0.61), major bleeding (p _int= 0.76), and MACCE (p _int= 0.80) were consistent without significant interaction compared with ticagrelor-based 12-month DAPT. The treatment effects according to the BMI quartiles and age, sex, and diabetic status were also consistent without significant interaction.

Conclusion

The BMI-dependent impact of ticagrelor monotherapy after 3-month DAPT compared with 12-month DAPT on clinical outcomes was not heterogeneous in patients with ACS.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [NCT02494895].

P2Y12 Antagonists in Cardiovascular Disease—Finding the Best Balance Between Preventing Ischemic Events and Causing Bleeding

Dual antiplatelet therapy comprising of aspirin and oral P2Y₁₂ receptor antagonists are an established cornerstone of therapy in acute coronary syndromes and percutaneous coronary intervention. As a result, the platelet P2Y₁₂ receptor remains a key therapeutic target in cardiovascular medicine since pharmacological antagonists were first developed in the 1990’s. With a greater understanding of platelet biology and the role played by the P2Y₁₂ receptor in the amplification of platelet activation and thrombus formation, there has been progressive refinement in the development of P2Y₁₂ receptor antagonists with greater potency and consistency of antiplatelet effect. However, challenges remain in the utilization of these agents particularly in balancing the need for greater protection from ischemic events whilst minimizing the bleeding risk and present a real opportunity for the institution of individualized medicine. Future drug developments will provide clinicians with greater avenues to achieve this.

Ticagrelor With or Without Aspirin in Chinese Patients Undergoing Percutaneous Coronary Intervention: A TWILIGHT China Substudy

BACKGROUND

The risk/benefit tradeoff of dual antiplatelet therapy after percutaneous coronary intervention may vary in East Asian patients as compared with their non-East Asian counterparts.

METHODS

The double-blind, placebo-controlled, randomized TWILIGHT trial (Ticagrelor With Aspirin or Alone in High-Risk Patients After Coronary Intervention) enrolled patients undergoing high-risk percutaneous coronary intervention. After 3 months of treatment with ticagrelor plus aspirin, event-free and adherent patients remained on ticagrelor and were randomly assigned to receive aspirin or placebo for 1 year. The primary end point was Bleeding Academic Research Consortium type 2, 3, or 5 bleeding; the key secondary end point was the first occurrence of death from any cause, nonfatal myocardial infarction, or nonfatal stroke.

RESULTS

Of 9006 enrolled and 7119 randomized patients in TWILIGHT, 1169 patients (13.0%) were enrolled at 27 Chinese sites in this prespecified substudy, of whom 1028 (14.4%) patients were randomized after 3 months. The incidence of the primary end point was 6.2% in the ticagrelor+aspirin group versus 3.5% in the ticagrelor+placebo group between randomization and 1 year (hazard ratio, 0.56 [95% CI, 0.31-0.99]; P=0.048). The key secondary end point occurred in 3.4% of patients in the ticagrelor+aspirin group versus 2.4% in the ticagrelor+placebo group (hazard ratio, 0.70 [95% CI, 0.33-1.46]; P=0.34). There was no interaction between the region of randomization (China versus the rest of the world) and randomized treatment assignment in terms of the primary or key secondary end points.

CONCLUSIONS

Ticagrelor monotherapy significantly reduced clinically relevant bleeding without increasing ischemic events as compared with ticagrelor plus aspirin in Chinese patients undergoing high-risk percutaneous coronary intervention.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02270242.

Effect of CYP4F2 Polymorphisms on Ticagrelor Pharmacokinetics in Healthy Chinese Volunteers

Background: Ticagrelor belongs to a new class of P2Y₁₂ receptor inhibitor that has been widely used for antiplatelet therapy. This study aimed to explore the effect of single nucleotide polymorphisms (SNPs) in metabolic enzymes, transporters, and other relevant variants on the pharmacokinetics (PK) of ticagrelor and its active metabolite, AR-C124910XX.

Methods: The study population comprised 68 healthy Chinese volunteers who were enrolled in a ticagrelor bioequivalence clinical trial. The PK profile of ticagrelor was evaluated after orally administering a single 90-mg dose of ticagrelor in tablet form. The plasma concentrations of ticagrelor and AR-C124910XX were determined through liquid chromatography–tandem mass spectrometry. Plasma DNA samples were used to explore the effect of gene polymorphisms on the PK of ticagrelor and AR-C124910XX with whole-exome sequencing.

Results: Female participants had a higher maximum plasma concentration/weight ratio (C_max/W; p < 0.001) and a shorter half-life (T_1/2; p < 0.05) for ticagrelor than their male counterparts. In addition, a higher area under the curve/weight ratio (AUC/W; p < 0.001), and longer T_1/2 (p < 0.001) and time to reach the maximum plasma concentration (T_max; p < 0.001), as well as a lower apparent drug clearance (CL/F; p < 0.001), were observed among healthy volunteers in the fed trial compared to those enrolled in the fasting trial. For AR-C124910XX, higher C_max/W (p < 0.001) and AUC/W (p < 0.001) but lower CL/F (p < 0.001) and apparent volume of distribution (V_d/F; p < 0.001) were observed among female participants. Healthy volunteers enrolled in the fasting trial exhibited higher C_max/W (p < 0.001) and AUC/W (p < 0.01), shorter T_max (p < 0.001), and lower CL/F (p < 0.001) and V_d/F (p < 0.001) than those enrolled in the fed trial. Upon confirmation through multivariate analysis, the CYP4F2 rs2074900 A/A carriers were associated with higher C_max/W and AUC/W and lower CL/F and V_d/F than the CYP4F2 rs2074900 A/G and G/G carriers.

Conclusion: This study is the first to show that the CYP4F2 rs2074900 SNP had a remarkable effect on ticagrelor PK, which is significant since it adds to the limited pharmacogenetic information on ticagrelor.

Ticagrelor Monotherapy After 3-Month Dual Antiplatelet Therapy in Acute Coronary Syndrome by High Bleeding Risk: The Subanalysis From the TICO Trial

This study demonstrated that for acute coronary syndrome patients treated with drug eluting stents, high bleeding risk (HBR) was associated with higher rates of net adverse clinical events (NACEs), not only including bleeding but also ischemic events. Ticagrelor monotherapy after 3-month dual antiplatelet therapy (DAPT) was associated with lower rates of NACEs and major bleeding than ticagrelor-based 12-month DAPT regardless of HBR, with no significant interaction between therapy and HBR. These findings were consistent regardless of HBR definition by Academic Research Consortium for HBR criteria or by Predicting Bleeding Complications in Patients Undergoing Stent Implantation and Subsequent DAPT score.

Background and Objectives

Identifying patients with high bleeding risk (HBR) is important when making decisions for antiplatelet therapy strategy. This study evaluated the impact of ticagrelor monotherapy after 3-month dual antiplatelet therapy (DAPT) according to HBR in acute coronary syndrome (ACS) patients treated with drug eluting stents (DESs).

Methods

In this post-hoc analysis of the TICO trial, HBR was defined by 2 approaches: meeting Academic Research Consortium for HBR (ARC-HBR) criteria or Predicting Bleeding Complications in Patients Undergoing Stent Implantation and Subsequent DAPT (PRECISE-DAPT) score ≥25. The primary outcome was a 3–12 months net adverse clinical event (composite of major bleeding and adverse cardiac and cerebrovascular events).

Results

Of the 2,980 patients without adverse events during the first 3 months after DES implantation, 453 (15.2%) were HBR by ARC-HBR criteria and 504 (16.9%) were HBR by PRECISE-DAPT score. The primary outcome rate was higher in HBR versus non-HBR patients (by ARC-HBR criteria: hazard ratio [HR], 2.87; 95% confidence interval [CI], 1.76–4.69; p<0.001; by PRECISE-DAPT score: HR, 3.09; 95% CI, 1.92–4.98; p<0.001). Ticagrelor monotherapy after 3-month DAPT was associated with lower primary outcome rate than ticagrelor-based 12-month DAPT regardless of HBR by ARC-HBR criteria, with similar magnitudes of therapy effect for HBR and non-HBR patients (p-interaction=0.400). Results were consistent by PRECISE-DAPT score (p-interaction=0.178).

Conclusions

In ACS patients treated with DESs, ticagrelor monotherapy after 3-month DAPT was associated with lower rate of adverse clinical outcomes regardless of HBR, with similar magnitudes of therapy effect between HBR and non-HBR.

Trial Registration

ClinicalTrials.gov Identifier: NCT02494895

Long-Term Ticagrelor in Patients With Prior Coronary Stenting in the PEGASUS-TIMI 54 Trial

Background Coronary stent type and risk of stent thrombosis remain important factors affecting recommended duration of dual antiplatelet therapy. We investigated the efficacy and safety of long-term ticagrelor in patients with prior coronary stenting enrolled in the PEGASUS-TIMI 54 (Prevention of Cardiovascular Events in Patients with Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin-Thrombolysis in Myocardial Infarction 54) trial. Methods and Results Patients in PEGASUS-TIMI 54 had a myocardial infarction 1 to 3 year prior and were randomized 1:1:1 to ticagrelor 60 or 90 mg BID or placebo. The primary end point was a composite of cardiovascular death, myocardial infarction, or stroke (major adverse cardiovascular events). Stent thrombosis was prospectively adjudicated (Academic Research Consortium definition). Baseline characteristics were compared by most recent stent type (bare metal versus drug-eluting stent and first- versus later-generation drug-eluting stent). Treatment arms were compared using Cox proportional hazards models. Of 21 162 patients randomized, 80% (n=16 891) had prior coronary stenting. Following randomization, myocardial infarction was the most frequent ischemic event in patients with prior stenting in the placebo arm, occurring in 5.2% of patients (Type 1: 4.1%), followed by cardiovascular death (2.3%), stroke (1.7%), and stent thrombosis (0.9%). Ticagrelor_pooled reduced major adverse cardiovascular events (7.0% versus 8.0%; hazard ratio [HR], 0.85; 95% CI, 0.75-96) regardless of stent type (bare metal stent versus drug-eluting stent: p_interaction=0.767; first versus later generation: p_interaction=0.940). The rate of any stent thrombosis was numerically lower with ticagrelor_pooled (0.7% versus 0.9%; HR, 0.73; 95% CI, 0.50-1.05) and Thrombolysis in Myocardial Infarction major bleeding was increased (HR, 2.65; 95% CI, 1.90-3.68). Conclusions Long-term ticagrelor reduces major adverse cardiovascular events in patients with prior myocardial infarction and coronary stenting regardless of stent type, with the benefit driven predominantly by reduction in de novo events. Nonfatal major bleeding is increased with ticagrelor. Registration Information clinicaltrials.gov. Identifier: NCT01225562.

Ticagrelor Monotherapy Versus Ticagrelor With Aspirin in Patients With ST-Segment Elevation Myocardial Infarction

OBJECTIVES

The aim of this study was to assess whether the effects of ticagrelor monotherapy after 3-month dual-antiplatelet therapy (DAPT) are consistent among patients presenting with ST-segment elevation myocardial infarction (STEMI), non-ST-segment elevation myocardial infarction, and unstable angina treated with drug-eluting stents.

BACKGROUND

Ticagrelor monotherapy after short-term DAPT has not been investigated in patients with STEMI.

METHODS

This was a pre-specified, stratified, subgroup analysis of the STEMI cohort from the TICO (Ticagrelor Monotherapy After 3 Months in the Patients Treated With New Generation Sirolimus Stent for Acute Coronary Syndrome) trial, which constituted 36% of the total population. The primary outcome was a composite of major bleeding and major adverse cardiac and cerebrovascular events (MACCE; death, myocardial infarction, stent thrombosis, stroke, or target vessel revascularization). The secondary outcomes were major bleeding and MACCE.

RESULTS

The incidence of the primary outcome was 4.4% in patients with STEMI (n = 1,103), 6.0% in those with non-ST-segment elevation myocardial infarction (n = 1,027), and 4.1% in those with unstable angina (n = 926), without statistical significance (p = 0.09). Compared with ticagrelor-based 12-month DAPT, ticagrelor monotherapy after 3-month DAPT showed consistent effects on the primary outcome across clinical presentations (p for interaction [p_int] = 0.64). Furthermore, the effect of ticagrelor monotherapy on the reduction of major bleeding was consistent across clinical presentations (p_int = 0.36). The effect of ticagrelor monotherapy on MACCE was also consistent in patients with STEMI, without evidence of a higher risk for MACCE (p_int = 0.14).

CONCLUSIONS

This pre-specified subgroup analysis revealed no heterogeneity in the effects of ticagrelor monotherapy after 3-month DAPT, compared with 12-month DAPT, for the primary outcome, major bleeding, and MACCE across clinical presentations including STEMI, though larger studies are needed to demonstrate these findings with adequate power. (Ticagrelor Monotherapy After 3 Months in the Patients Treated With New Generation Sirolimus Stent for Acute Coronary Syndrome [TICO Study]; NCT02494895).

Ticagrelor Monotherapy Versus Ticagrelor With Aspirin in Acute Coronary Syndrome Patients With a High Risk of Ischemic Events

[Figure: see text].

Impact of preprocedural coronary flow grade on duration of dual antiplatelet therapy in acute myocardial infarction

We investigated the impact of pre-percutaneous coronary intervention (pre-PCI) thrombolysis in myocardial infarction (TIMI) flow grade (pre-TIMI) on 3-month (3-mo) and 12-mo of dual antiplatelet therapy (DAPT) in patients with acute myocardial infarction (AMI). This was a post hoc analysis of the TICO trial. A total of 2083 patients with AMI (pre-TIMI 0/1: n = 1143; pre-TIMI 2/3: n = 940) were evaluated. The primary outcome was the occurrence of net adverse clinical events (NACE), defined as a composite of TIMI major bleeding and major adverse cardiac and cerebrovascular events (MACCE) within 12-mo following PCI. The secondary outcomes were the occurrence of the individual components of TIMI bleedings and MACCE. In the pre-TIMI 0/1 group, the primary and second outcomes were not significantly different between the 3-mo and 12-mo DAPT groups. However, in the pre-TIMI 2/3 group, the occurrences of TIMI minor (adjusted hazard ratio [aHR]: 0.294; p = 0.016) and major or minor bleeding (aHR: 0.483; p = 0.014) on intention-to-treat analysis were significantly higher in the 12-mo than in the 3-mo DAPT group. The occurrence of MACCE was similar between the two groups. A higher bleeding tendency in 12-mo DAPT compared with 3-mo DAPT was more obvious in the pre-TIMI 2/3 group than in the pre-TIMI 0/1 group.Clinical Trial Registration: URL: http://www.clinicaltrials.gov . Unique identifier: NCT02494895.

Ischemic and Bleeding Events of Ticagrelor Monotherapy in Korean Patients With and Without Diabetes Mellitus: Insights From the TICO Trial

Background: Ticagrelor monotherapy after 3 months dual antiplatelet therapy (DAPT) with aspirin and ticagrelor can reduce bleeding without increasing ischemic events after percutaneous coronary intervention (PCI). However, the impact of this approach among the patient with diabetes remains unknown.

Methods: This was a sub-analysis of the Ticagrelor Monotherapy after 3 months in the Patients Treated with New Generation Sirolimus Eluting Stent for Acute Coronary Syndrome (TICO) trial. After successful PCI, the patients were randomly assigned to ticagrelor monotherapy after 3-months DPAT or to ticagrelor-based 12-months DAPT. We compared ischemic events and bleeding events between the patients with diabetes and without diabetes for 12 months. Ischemic events were defined as death, myocardial infarction, ischemic stroke, transient ischemic attack, stent thrombosis, and any revascularizations. Bleeding events were defined according to the Thrombolysis in Myocardial Infarction (TIMI) criteria and Bleeding Academic Research Consortium (BARC) definition.

Results: Between August 2015 and October 2018, 3,056 patients were enrolled in the TICO trial, of which 835 (27.3%) had diabetes mellitus. Diabetes mellitus was associated with all evaluated ischemic and bleeding events. No significant differences in any ischemic events were observed in patients with diabetes between ticagrelor monotherapy after 3-months DAPT and ticagrelor-based 12-months DAPT (hazard ratio [HR] 0.83, 95% confidence interval [CI] 0.45–1.52, p = 0.540). In patients with diabetes, the overall incidence of bleeding complications during the 12-months follow-up period did not differ between the two treatment groups (HR 0.83, 95% CI 1.48–1.43, p = 0.505). However, ticagrelor monotherapy was significantly reduced both any TIMI bleeding and BARC three or five bleeding events in diabetes patients in the 3-months landmark analysis, after 3-months DAPT period (HR 0.20, 95% CI 0.07–0.59, p = 0.003).

Conclusion: In diabetic patients, ticagrelor monotherapy showed a lower incidence of bleeding complications after 3-months DAPT period, without increasing ischemic complications, compared with ticagrelor-based 12-months DAPT (ClinicalTrials.gov Identifier: NCT02494895).

The dawn of aspirin free strategy after short term dual antiplatelet for percutaneous coronary intervention: meta-analysis of randomized controlled trials

There is still a debate about the safety and efficacy of an aspirin free strategy after percutaneous coronary intervention (PCI). Hence, we performed a meta-analysis comparing aspirin free strategy to dual antiplatlets therapy (DAPT). Randomized trials (RCTs) comparing aspirin free strategy to DAPT in patients who received PCI were included. The primary outcome of interest was bleeding, defined per the Bleeding Academic Research Consortium (BARC). Secondary outcomes included major adverse cardiovascular and cerebrovascular events (MACE); defined as all-cause mortality, myocardial infarction or stroke, the individual component of MACE and stent thrombosis. A total of 4 RCTs with 29,089 patients were included. There was significant reduction in BARC 2,3 or 5 bleeding events in patients who were treated with aspirin free strategy versus DAPT (HR 0.61, 95% CI 0.39-, p = 0.03, I² = 89%). Moreover, although there was a trend of reduced major bleeding (BARC 3 or 5) outcomes in the aspirin free strategy group compared to the DAPT group, this did not achieve statistical significance (HR 0.63, 95% CI 0.37-1.06, p = 0.08, I² = 795). Additionally, there was no difference between the aspirin free strategy and DAPT in term of MACE (HR 0.92, 95% CI 0.82-1.03, p = 0.13, I² = 0%), all-cause mortality (HR 0.89, 95% CI 0.77-1.04, p = 0.15, I² = 0%), MI (HR 0.89, 95% CI 0.74-1.08, p = 0.24, I² = 0%), stroke (HR 1.13, 95% CI 0.65-1.99, p = 0.66, I² = 60%) or stent thrombosis (HR 0.1.01, 95% CI 0.83-1.22, p = 0.93, I² = 0%). Aspirin free strategy is as effective as DAPT in reducing MACE with better safety profile in term of bleeding.

An updated drug profile of ticagrelor with considerations on the treatment of patients with coronary artery disease and diabetes mellitus

INTRODUCTION

Ticagrelor is an antiplatelet agent acting through direct and reversible competitive inhibition of the platelet P2Y₁₂ receptor. While the clinical merits of ticagrelor in patients who experienced an acute coronary syndrome are widely accepted, its role in stable coronary artery disease is less established. Recently, large-scale trials of ticagrelor have been published in this setting, including a trial in patients with diabetes mellitus (DM).

AREAS COVERED

This review aims to inform about recent findings on ticagrelor, by appraising the current body of evidence on its use in different clinical scenarios, particularly in DM, ranging from pharmacology to clinical outcomes and future directions.

EXPERT OPINION

The results of the THEMIS trial, conducted in DM patients with stable coronary artery disease and no prior stroke or myocardial infarction, showed that although ticagrelor in addition to aspirin reduced the risk of ischemic events, this was associated with a parallel increase in bleeding complications. However, patients with history of percutaneous coronary intervention seemed to benefit more from adjunctive ticagrelor therapy. Careful bleeding and ischemic risk stratification remains crucial to define the best antithrombotic strategy for the individual patient.

Abbreviated Dual Antiplatelet Therapy Followed by P2Y12 Inhibitor Monotherapy versus 12 Months' Dual Antiplatelet Therapy Post Percutaneous Coronary Intervention: A Systematic Review and Meta-analysis of Randomized Controlled Trials

INTRODUCTION

An increased incidence of stent thrombosis after implantation of first-generation drug-eluting stents led to a recommendation of dual antiplatelet therapy (DAPT) for 12 months after the procedure. However, given the use of second-generation and newer drug-eluting stents, this recommendation needs to be revisited. Several randomized controlled trials (RCTs) have studied an abbreviated DAPT regimen of ≤ 3 months followed by P2Y₁₂ inhibitor monotherapy, and results have been conflicting.

OBJECTIVE

We performed a systematic review with meta-analysis of RCTs of abbreviated DAPT for ≤ 3 months followed by P2Y₁₂ monotherapy compared with 12 months of DAPT.

METHODS

We performed a systematic search of the MEDLINE/PubMed, Cochrane, and DARE (Database of Abstracts of Reviews of Effects) databases for eligible RCTs. Quantitative analysis was performed based on the intention-to-treat principle. We used the Mantel-Haenszel method with a random-effects model to calculate relative risks (RRs) with 95% confidence intervals (CIs).

RESULTS

The final analysis included four RCTs. We found no difference in the risk of all-cause mortality (RR 0.90; 95% CI 0.77-1.05; p = 0.18; I² = 0%; χ²p = 0.58), myocardial infarction (RR 0.99; 95% CI 0.86-1.15; p = 0.85; I² = 0%; χ²p = 0.70), stroke (RR 1.14; 95% CI 0.65-1.98; p = 0.65; I² = 59%; χ²p = 0.06), or stent thrombosis (RR 0.98; 95% CI 0.73-1.33; p = 0.90; I² = 0%; χ²p = 0.48). Additionally, there was no difference in the risk for major bleeding, defined as BARC (Bleeding Academic Research Consortium) type 3 or 5, between the two groups (RR 0.62; 95% CI 0.37-1.05; p = 0.07; I² = 79%; χ²p < 0.05).

CONCLUSION

Abbreviated DAPT followed by P2Y₁₂ monotherapy resulted in a similar risk of re-ischemic clinical outcomes post percutaneous coronary intervention as compared with the standard 12-month DAPT regimen. The risk of major bleeding (BARC type 3 or 5) also remained similar between the two groups. However, as trials have reported benefits with abbreviated DAPT followed by P2Y₁₂ monotherapy in terms of combined endpoints and all bleeding (BARC type 2-5), additional research is needed.

Antithrombotic Therapy in Myocardial Infarction: Historic Perils and Current Challenges-A 70-Year Journey

There have been numerous and intriguing advancements in antithrombotic therapy for myocardial infarction since it was described in the earliest issues of Thrombosis and Haemostasis. In this article, we revisit historical breakthroughs and describe the four most challenging contemporary themes relating to antithrombotic therapy in myocardial infarction. In all four, the challenge is to find the best balance of reducing specific levels of ischaemic risks without increasing bleeding risk. The first is the question of the optimal duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI). This includes discussion of monotherapy after a period of DAPT. The second relates to the role of genotype and phenotype-guided individualisation of antiplatelet therapy. There is emerging evidence for a role of pheno/genotyping in identifying individuals at high risk for recurrent ischaemic events or in guiding the timing of cardiac surgery for patients on DAPT. The third addresses the increasing evidence for dual pathway inhibition, for example, with rivaroxaban in addition to aspirin in patients where high ischaemic and low bleeding risk is demonstrated. Finally the fourth highlights the challenge of the most appropriate combination of antiplatelet and anticoagulation therapy for patients with known atrial fibrillation after PCI. In most individuals, oral P₂Y₁₂ inhibitor therapy combined with a direct acting oral anticoagulant appears to be the best strategy based on the available evidence. Overall, the progress in antithrombotic therapy achieved over the last seven decades is remarkable, however, there are important issues to address and progress still to be made.

P2Y12 Inhibitor Monotherapy After a Short Dual Antiplatelet Therapy Versus Standard-Term Dual Antiplatelet Therapy in Patients Undergoing Percutaneous Coronary Intervention: A Contemporary Meta-Analysis

BACKGROUND AND OBJECTIVES

Dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) reduces the incidence of thrombotic events but increases the risk of bleeding, which is associated with a substantial and durable risk of death and could offset the benefits of a reduction in thrombotic events. P2Y12 inhibitor monotherapy after short-term DAPT could be an option to reduce the risk of bleeding. We carried out a meta-analysis comparing P2Y12 inhibitor monotherapy after short-term DAPT with standard-term DAPT in patients undergoing PCI.

METHODS

We searched the PubMed and EMBASE databases through 11 April 2020. Two authors independently reviewed and selected eligible trials. The DerSimonian-Laird method with the binary random-effects model was used to calculate the relative risk (RR) with 95% confidence interval (CI).

RESULTS

Five trials involving 23,762 patients were included in the final analyses; four were open-label trials, while the TWILIGHT trial was double-blinded. Ticagrelor was used in three trials, and the other two trials included several P2Y12 inhibitors. P2Y12 inhibitor monotherapy after short-term DAPT significantly reduced the bleeding events, defined as Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding and Thrombolysis in Myocardial Infarction (TIMI) major or minor bleeding, by 39% (RR 0.61, 95% CI 0.38-0.99; p = 0.045) and 46% (RR 0.56, 95% CI 0.42-0.73; p < 0.001), respectively. A significant reduction in cardiovascular death was associated with P2Y12 inhibitor monotherapy after short-term DAPT (RR 0.75, 95% CI 0.58-0.98; p = 0.037; I² = 0). No significant difference in all-cause mortality, myocardial infarction, stroke, or definite or probable stent thrombosis was observed.

CONCLUSIONS

This meta-analysis showed a significantly lowered risk of major bleeding and similar benefits of P2Y12 inhibitor monotherapy after short-term DAPT compared with standard-term DAPT in patients undergoing PCI.

P2Y12 inhibitors monotherapy after short course of dual antiplatelet therapy in patients undergoing percutaneous coronary intervention: a meta-analysis of randomized clinical trials including 29 089 patients

AIMS

Dual antiplatelet therapy (DAPT) reduces the incidence of thrombotic complications at the cost of an increase in bleedings. New antiplatelet therapies focused on minimizing bleeding and maximizing antithrombotic effects are emerging. The aim of this study is to collect the current evidence coming from randomized controlled trials (RCTs) on early aspirin interruption after percutaneous coronary intervention (PCI) and current drug-eluting stent (DES) implantation and to perform a meta-analysis in order to evaluate the safety and efficacy of this strategy.

METHODS AND RESULTS

MEDLINE/PubMed was systematically screened for RCTs comparing P2Y12 inhibitors (P2Y12i) monotherapy after a maximum of 3 months of DAPT (S-DAPT) vs. DAPT for 12 months (DAPT) in patients undergoing PCI with DES. Baseline features were appraised. Major adverse cardiac and cerebrovascular events (MACCE: all causes of death, myocardial infarction, and stroke) and its single composites, stent thrombosis (ST) and Bleeding Academic Research Consortium (BARC) type 3 or 5 were considered and pooled with fixed and random-effects with inverse-variance weighting. A total of four RCTs including a total of 29 089 patients were identified. Overall, the majority of included patients suffered a stable coronary artery disease, while ST-elevation myocardial infarction was the least represented clinical presentation. Complex anatomical settings like left main intervention, bifurcations, and multi-lesions treatment were included although representing a minor part of the cases. At 1-year follow-up, MACCE rate was similar [odds ratio (OR) 0.90; 95% confidence intervals (CIs) 0.79-1.03] and any of its composites (all causes of death rate: OR 0.87; 95% CIs 0.71-1.06; myocardial infarction: OR 1.06; 95% CIs 0.90-1.26; stroke: OR 1.12; 95% CIs 0.82-1.53). Similarly, also ST rate was comparable in the two groups (OR 1.17; 95% CIs 0.83-1.64), while BARC 3 or 5 bleeding resulted significantly lower, adopting an S-DAPT strategy (OR 0.70; 95% CIs 0.58-0.86).

CONCLUSION

After a PCI with current DES, an S-DAPT strategy followed by a P2Y12i monotherapy was associated with a lower incidence of clinically relevant bleeding compared to 12 months DAPT, with no significant differences in terms of 1-year cardiovascular events.

Effect of Ticagrelor Monotherapy vs Ticagrelor With Aspirin on Major Bleeding and Cardiovascular Events in Patients With Acute Coronary Syndrome: The TICO Randomized Clinical Trial

IMPORTANCE

Discontinuing aspirin after short-term dual antiplatelet therapy (DAPT) was evaluated as a bleeding reduction strategy. However, the strategy of ticagrelor monotherapy has not been exclusively evaluated in patients with acute coronary syndromes (ACS).

OBJECTIVE

To determine whether switching to ticagrelor monotherapy after 3 months of DAPT reduces net adverse clinical events compared with ticagrelor-based 12-month DAPT in patients with ACS treated with drug-eluting stents.

DESIGN, SETTING, AND PARTICIPANTS

A randomized multicenter trial was conducted in 3056 patients with ACS treated with drug-eluting stents between August 2015 and October 2018 at 38 centers in South Korea. Follow-up was completed in October 2019.

INTERVENTIONS

Patients were randomized to receive ticagrelor monotherapy (90 mg twice daily) after 3-month DAPT (n = 1527) or ticagrelor-based 12-month DAPT (n = 1529).

MAIN OUTCOMES AND MEASURES

The primary outcome was a 1-year net adverse clinical event, defined as a composite of major bleeding and adverse cardiac and cerebrovascular events (death, myocardial infarction, stent thrombosis, stroke, or target-vessel revascularization). Prespecified secondary outcomes included major bleeding and major adverse cardiac and cerebrovascular events.

RESULTS

Among 3056 patients who were randomized (mean age, 61 years; 628 women [20%]; 36% ST-elevation myocardial infarction), 2978 patients (97.4%) completed the trial. The primary outcome occurred in 59 patients (3.9%) receiving ticagrelor monotherapy after 3-month DAPT and in 89 patients (5.9%) receiving ticagrelor-based 12-month DAPT (absolute difference, -1.98% [95% CI, -3.50% to -0.45%]; hazard ratio [HR], 0.66 [95% CI, 0.48 to 0.92]; P = .01). Of 10 prespecified secondary outcomes, 8 showed no significant difference. Major bleeding occurred in 1.7% of patients with ticagrelor monotherapy after 3-month DAPT and in 3.0% of patients with ticagrelor-based 12-month DAPT (HR, 0.56 [95% CI, 0.34 to 0.91]; P = .02). The incidence of major adverse cardiac and cerebrovascular events was not significantly different between the ticagrelor monotherapy after 3-month DAPT group (2.3%) vs the ticagrelor-based 12-month DAPT group (3.4%) (HR, 0.69 [95% CI, 0.45 to 1.06]; P = .09).

CONCLUSIONS AND RELEVANCE

Among patients with acute coronary syndromes treated with drug-eluting stents, ticagrelor monotherapy after 3 months of dual antiplatelet therapy, compared with ticagrelor-based 12-month dual antiplatelet therapy, resulted in a modest but statistically significant reduction in a composite outcome of major bleeding and cardiovascular events at 1 year. The study population and lower than expected event rates should be considered in interpreting the trial.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02494895.

Effect of P2Y12 inhibitor monotherapy versus dual antiplatelet therapy on cardiovascular events in patients undergoing percutaneous coronary intervention: systematic review and meta-analysis

INTRODUCTION

Clinical data on short mandatory dual antiplatelet therapy (DAPT) followed by P2Y12 inhibitor monotherapy, compared with prolonged DAPT in patients undergoing percutaneous coronary intervention (PCI) are insufficient. We aim to evaluate the effectiveness and safety of P2Y12 inhibitor monotherapy and prolonged DAPT after short mandatory DAPT on cardiovascular events in patients undergoing PCI.

EVIDENCE ACQUISITION

A systematic literature search was performed in seven medical databases from building the database until July 2019. Three studies with randomized controlled trial (RCTs), totaling 21,970 patients, were included in this meta-analysis. The included studies were assessed by the Cochrane risk of bias and analyzed by Review Manager v. 5.3 software.

EVIDENCE SYNTHESIS

Our result of pooled analysis showed that there was noninferior rates of in major adverse cardiac and cerebrovascular events (MACCE), stroke, myocardial infarction and cardiac death between short mandatory DAPT followed by P2Y12 inhibitor monotherapy and prolonged DAPT in patients undergoing PCI. Pooled analysis showed that short mandatory DAPT followed by P2Y12 inhibitor monotherapy could significantly reduce the risk of bleeding BARC type 2-5 (OR=0.47, 95% CI: 0.31-0.70, P=0.002), compared with prolonged DAPT in patients undergoing PCI. However, Pooled analysis showed that short mandatory DAPT followed by P2Y12 inhibitor monotherapy was not associated with BARC type 3-5, compared with prolonged DAPT.

CONCLUSIONS

This meta-analysis demonstrated that short mandatory DAPT followed by P2Y12 inhibitor monotherapy compared with prolonged DAPT resulted in noninferior rates of MACCE, all-cause mortality, cardiac death, stroke, myocardial infarction and stent thrombosis. Furthermore, short mandatory DAPT followed by P2Y12 inhibitor monotherapy could significantly reduce the risk of bleeding BARC type 2-5.

Omitting aspirin in PCI patients: Myth or reality?

In the current era of percutaneous coronary intervention (PCI), with the use of contemporary drug-eluting stents, refined techniques, and adjunctive pharmacotherapy, the role of aspirin peri-PCI remains undisputable. Beyond the initial period, dual antiplatelet therapy (DAPT) consisting of aspirin and a P2Y₁₂ receptor inhibitor for 6 months in stable coronary artery disease and 12 months in acute coronary syndromes is the standard of care. However, concerns regarding bleeding adverse events caused by aspirin have led to shortened DAPT duration or even omission of aspirin. Aspirin free-strategies have been increasingly encountered in several studies and showed a significant reduction in bleeding events, without any sign of increased ischemic risk. Individualization of DAPT duration particularly in high bleeding risk patients appears therefore mandatory, making aspirin not necessary in several cases. Moreover, recent randomized trials have shed light on how to treat PCI patients in the presence of concomitant anticoagulant treatment with P2Y₁₂ monotherapy and excluding aspirin. These aspirin-free strategies have been proved safer than the "older" standard triple antithrombotic treatment, without compromising safety. Ongoing studies may further dispel the myths and establish real facts regarding post-PCI-tailored treatment with or without aspirin.

[Optimal duration of dual antiplatelet therapy after coronary stent placement or acute coronary syndrome. Is customisation possible?]

The recommended 6-month dual antiplatelet therapy (DAPT) after coronary angioplasty with implantation of a drug eluting stent is based on solid evidence, but must take into account continuous improvements in stent technology leading to reduced thrombogenicity. In stable patients with a high hemorrhagic risk, it is possible to reduce DAPT duration at 3 months without significant increase in the risks of ischemic events or stent thrombosis. Further reduction toward a 1-month DAPT is likely to involve new strategies of stopping aspirin at 1 month, and continuing long-term monotherapy with inhibitors of P2Y12 receptor. After acute coronary syndrome, it seems possible to reduce the duration of DAPT (standard, 12 months) in patients at high risk of bleeding. A 6-month DAPT, or even less, provides a good compromise between hemorrhagic risk and ischemic recurrences. Conversely, in patients who have fully tolerated a 12-month DAPT after infarction, and who are at very high risk of ischemic recurrence, the prolongation of a P2Y12 inhibitor in combination with aspirin may be considered, with a risk of haemorrhage almost double. A certain degree of customisation of the duration of DAPT is therefore possible, based on age, renal function, comorbidities, haemorrhagic history, and the use of risk scores (PRECISE-DAPT, DAPT).